From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C1740606A330 for ; Wed, 11 Nov 2026 15:06:38 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4jPn0s3B4yz30g6; Thu, 12 Nov 2026 02:06:37 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=213.95.11.211 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1794409597; cv=none; b=ihlQZ0HKq5+d07qykvS3Y3fnE2BrBlFI9YJASbR3DHk7VcHXagiTh6XCpjPsq8pQT8vk6l+4nshYM0Xv+hRX/4bcF7ZTXXrCkEZUnVmMrqNMem/Dtn/zb+RSh81zXdpNB0H9+tVATOEyXbVOZGpo+TY4MDJ1uhtl4AHWSGt6jzWv/j5pAB54oOe6LkYMaN16O+WlDHYDiPCesP/aYy1MyfxCfwHrwNQ08oJ41ouKOCT4LKjmuij+5sElix1I2xUcULPTG1V5YOD8paSuLaoa2q6eGaXjYV1foN8KoZpdURa/qCX3bPPdQkO0TCTDwWiFOcobmUq2t+Q8cjJHklCARg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1794409597; c=relaxed/relaxed; bh=uTScRtTvc50Ly2VnPZ+IRL7zVmHRGtRnjIEMUslXOU4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fSqYr0iknwRk5SiBDhK2PqTtpXjjgsoVeDFlHTJKZ1tujQDiTAtKz1SDBTlpCfklUrC8lziTw+dli5X7zo4sO/Goy5YPy+iYc5n3lIqlVraPj45dxE8CUOaeQPHGTB69WRSXaAXhN72JakmhevakEWjeE5miLiaUYM0cNYG8NJzouvHMJUFJKGkdR7DZbIjLBuWAiPYJijevqlkbbUuCo4Y6FafKaO+K/k1DJWd7zWpAh6FXAh1iRLxuSEew29/YNrn13gF/DZ2d+jDwPOy+KlrBwXkK1m1tGvVbCGk5AYXAt2YJoq0g2ScFrUHWbKPEB1oSBITKi0p2vv9Kf1qJQg== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=lists.ozlabs.org) smtp.mailfrom=lst.de Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=lists.ozlabs.org) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4jPn0r5Kypz30dj; Thu, 12 Nov 2026 02:06:36 +1100 (AEDT) Received: by verein.lst.de (Postfix, from userid 2407) id BF2AF68D09; Wed, 11 Nov 2026 15:56:47 +0100 (CET) Date: Wed, 11 Nov 2026 15:56:47 +0100 From: Christoph Hellwig To: Christian Brauner Cc: linux-fsdevel@vger.kernel.org, Jann Horn , Chris Mason , Josef Bacik , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Alexander Viro , Jan Kara , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, driver-core@lists.linux.dev, linux-mm@kvack.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, fuse-devel@lists.linux.dev, linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org, ocfs2-devel@lists.linux.dev, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org, Amir Goldstein , linux-erofs@lists.ozlabs.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH RFC 03/41] target: fileio: check that the backing file supports ->{read,write}_iter Message-ID: <20261111145647.GC9996@lst.de> References: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> <20261110-work-loop-pseudo-v1-3-4c998976c6c7@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , Precedence: list X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261110-work-loop-pseudo-v1-3-4c998976c6c7@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-Spam-Status: No, score=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Nov 10, 2026 at 10:14:19AM +0100, Christian Brauner wrote: > With fd_async_io=1 the fileio backend calls ->read_iter() and > ->write_iter() of the backing file directly. The synchronous path goes > through vfs_iter_read() and vfs_iter_write() which check for them but > the aio path doesn't. So a backing file without them calls a NULL > pointer on its first I/O. > > Refuse such files when configuring the device. On the synchronous path > every read or write that needed the missing method failed with EINVAL > anyway. Looks good: Reviewed-by: Christoph Hellwig